par glnc222 » Mer 18 Mai 2016 08:23
I have no special knowledge of battery sales to evaluate whether the offering is fake. You could search the internet for information on fakes. Also ask the vendor if they are Panasonic. They look exactly like cells shown by dealers who specify Panasonic. The "NCR" label and also separate part no. shown, seems to be uniquely Panasonic part id.
Because of the fire hazard with lithium use only genuine major brand batteries made with expensive intense quality control. Always recommended for cell phones and computers. The cheaper ones are for flashlights where the risk is less important.
It is important the maximum drain rate supports the device load and protection against over-discharge is supplied. The NCR18650B seems to fit, but everything is an experiment.
Also note those cells do not have welded tabs for soldering. This is an optional service supplied by the better battery vendors, specialty shops. It is more difficult, even dangerous, to solder onto lithium ion instead of other type batteries, without special skills and equipment (i.e. very fast to keep it cool). The German guy did it but mentioned his engineering skills and professional soldering equipment (which costs more than a battery pack). Commercially it is always done by welding with all types. The German dealer mentioned by Jean-Benoit offers these services and probably has these cells -- a full line dealer. You can also find cells with tabs sometimes on ebay. There are many vendors on ebay, AliExpress, Amazon, separate store websites, etc. Try Google.
The commercial AnewPow, LIthiumPowerInc Neato lithium batteries are LiNMC chemistry safer. The cells used by Jean Benoit I think are the same. They may have lower capacity so eight are needed. There is a wide variety of cell types made for different uses.
The two Neato compartments are connected by a wire inside around the back of the case. The low voltage side red wire (positive terminal) connects inside to the black wire on the high voltage side. The two Neato packs are in series. The two packs are used just to arrange the space properly. Botvac has a different spatial arrangement allowing a single pack.
So you have two cells in series in each compartment, connected by a protection board, and wired to the Neato connector (a standard Molex part 03-06-2042, .062" pins), on the red and black wires. (These smaller pins are not available in stores and usually must be ordered from a distributor such as Digi-Key, though might be on ebay or Aliexpress). The two yellow wires are to a thermistor or 10K ohm resistor. The thermistors need to be obtained from a discarded NiMh battery because that particular one, which we know, is usually available only in large industrial lots. Thermistors all vary in their temperature curves, and the software is calibrated to use this particular one. Since under SetConfig BatteryType 3 lithium, thermistors are not used to regulate charging, they could be replaced by a 10K ohm resistor (the thermistors are 10K ohms at 25C and decline with increasing temperature; they might read 11K at room temperature.)
You just need protection boards with at least a 4 amp capacity or even more, for the peak drive motor loads found in Neato operation (wiring an ammeter to it while it runs). Often 2-cell boards have lower current specs because lower voltage than 4-series, so interesting Jean Benoit found some good ones. The better pcb's seem to be at the specialty battery dealers with their own websites. They appear in Google web searches.
I have not made these batteries but experimented with other kinds. I do not presently have a Neato, playing with a Powerbot instead.
Technical info in thread "Lithium Ion Revisited", robotreviews.com. Good luck with the project. Maybe discuss with Jean Benoit locally?
Apologies to all the francofones. Perhaps this question should have been posted to the english site.